Regular gas won't hurt it. The Engine Control Unit just dials back the ignition timing to prevent pre-ignition (it has a knock sensor). The engine will produce a little less horsepower and mileage may suffer, but no engine damage will occur.

Dave

 

:you may be right but I don't think so. I know the cars of today with there computer are alot smarter than we are. If I thought Reg gas would really hurt my car I would run a better grade of gas.. The older cars use to tell you they didn't like the gas by knocking

 

DneprDave; Thanks for the encourgement.. My sellsman Told me I could run Reg GAs

 

Have you tried running the MINI recommended premium gas for a couple tankfuls and comparing what kind of mileage you get? As Dave mentioned, using the lower grade gas and causing the engine to detune itself to compensate is going to be detrimental to your mpg.

 

I had mine for afew months now and I don't drive too much but over 6 fillups here are the stats that I have from direct calculation (not the Instrument Computer):

All Shell Premium w/10% Ethanol:

Minimum MPG 25.09
Average MPG 26.07
Maximum MPG 27.41 (at the breakin Time that I was easy on gas)

I doubt that I can get any better with the combined MPG! (70% Highway-30% City)

 

Well today I filled up my mini with a tank of premium. I'm willing to give it a try ..


when I reset my MPG it read 35.1 mpg. looking forward to see what it going to read next. I promise to drive it the same way when I check it.

 

I have a 2009 Mini Clubman S and avarage about 20mpg. Does that sound right

Steve

 

Nope. Unless you are only tracking the car or spending close to 100% of your time in stop and go city traffic.

 

As jcauseyfd said.

But a questions for you. Are you reading that from the On Board Computer or are you hand calculating that.

If it is the computer than do a hand calculation for a few tanks and see what it really is and then if that is up in the 30 range and the computer is still in the low 20's then the computer need to be changed out or fixed.

 

Tires make a HUGE difference. Michelins in general have low rolling resistance. When we switched to the green X tire in my sig MPG went up 3 MPG on freeway trips. (Even though we stepped up a size from the OE 195/55/16 run flat Fred Flintstone tires).

Around town I don't bother checking MPG no matter if it's the MINI or my diesel truck, too many variables.

 

With only four tank fulls I am getting an average 33 mpg. That's mostly suburbs and "sport" off. Running 17s, a 6 speed and shifting between 3-4 k generally. Anything over 30 mpg is fine with me.

The R57 non S gets 2-3 mpg less, I guess it has to work harder and the cabriolet is heavier.

My $.02 worth

 

A couple of weeks ago, while surfing around, I was somehow distracted by one auto article that lead to another thant led to something about the Chevy Cruze. They offer a specific 'Eco' model which gets better fuel economy. On the GM site they discuss how the Eco model differs from the regular. It was noteworth 2 particular points:
■A lower front air dam extension, extensive use of underbody panels and a rear spoiler enhance aerodynamics
■A lowered ride height improves aerodynamics

Using the same logic, a lowered MINI, with JCW cow-catcher and JCW underbody panels should see improved fuel economy. That is unless you use the new 'features' as an excuse to drive faster

PS Higher octane gas w/o Ethanol will also give you better milage

 

I monitor and hand-calculate my MPG at every fill-up. I'm not really that ****, I just made a habit out of it years ago and it has helped me catch issues with my other cars before the engine computer would even light up.

Anyways, I have a 2010 Clubman S, auto, 17 inch run flats and I seem to average around 27 MPG around town. This is usually just short trips and a very short commute (5 miles). On the highway it all depends on what I set the Cruise control on. I've averaged as much as 33 MPG setting it at about 75MPH, to about 31 MPG setting it at about 83 MPH. Like the others have said, calculate it by hand a few times. Your computer's calculator may be off a good bit.

 

Go ethanol free www.pure-gas.org Your car will thank you. I have noticed an increase in mileage as well. My car runs better gets better mileage and my oil is cleaner. Less carbon I think. Around my area, it's about 15-20 cents more at the station that sells it. But worth every extra penny.

 

I calculate mileage by hand as well at every fill up..
I have had my clubman(2011) for a couple of months and i drive about 40miles a day commuting around town.. I have seen my mileage improve over the past two fill ups..
I am now past the 1200 mile break in period and i also feel that i have gotten to know my car better and adjusted my driving style ..

i was averaging around 27+ in the first few times and the past 2 fill ups around 30mpg..

 

Harlm1KW, How did it go? I'm curious to see if there is any difference between premium and regular in your Mini.

In school I took an automotive engineering class and they had a special motor with a knock sensor in a lab that could rate octane. We were told people are generally passionate about the brand and grade of gas they use and to go to your best station and bring in a sample of regular gas to test. I will always remember the results of our sample. We did multiple runs to make sure results were repeatable. At least on that day ARCO regular beat Chevron, 76 and Shell. Someone also brought premium and I remember there was not really that much difference that we could detect between the winning Arco regular and the premium.

I have some racing experience too with Motorcycles and we have dyno tested 104 octane race gas against 91 octane premium and at least on a stock motor (with 12:1 compression) there was almost no difference in hp (I think there was .25 more hp with the race gas).

My guess is you will have similar results on a single tank. I suspect octane is controlled more within a tolerance as opposed to being exactly 87 or exactly 91. You may eventually get a tank with really low octane and theoretically over time predetonation, especially on our aluminum heads and blocks can blow a head gasket. But still there are so many variables in how the car was made and how it was maintained, where it is being driven, even that is a crapshoot.

 

Almost through break-in, and I'm hovering right around 31.3 mpg with a good mix of long, cruisy bits, city bits, and lovingly mashing on the gas pedal every now and again...I could probably have it above 32 if I left out that last bit...

 

I paid $4.00 a gallon today to fill up with 90 octane, which is the highest octane I can get in my area (Alaska)

It was almost $60 to fill up

 

I used Premium most of the time with El Kabong. Occasionally when I'd do a fill up at half a tank I'd add Regular. I figured if the half in the tank was 93 octane and I added half a tank of 89 octane it would average out to 91. Is this totally off base?
Anyway, the last road trip I took in El Kabong he averaged 36mpg. I was pretty pleased with it. It was in July thru GA and FL so I was running the A/C on super cold most of the trip and we were totally packed to the gills with luggage. It seemed to me El Kabong's mpg improved over the years, or maybe I learned how to drive more conservatively .
Annette

 

Nope. In rough terms, that's how they do it at the pumps. The station's tanks only hold the lowest and highest octane ratings they sell; the two fuel grades are blended within the pump mechanism to give you the grade you've selected.

Incidentally, interesting name for your MINI; I'd forgotten that cartoon character's "alter ego..."

 

Thanks.
I loved Quick Draw (actually I loved all the Hanna-Barbara cartoons) as a kid. Alas my El Kabong is no more. He was totaled about a month ago and I miss him terribly. I couldn't get another Pepper White so I went with Horizon Blue. I almost named the new one Baba Bluey, but the name "GoKart Mozart" got stuck in my head, so the new one will be Mozart.
Annette

 

Bummer! Sorry to hear that "El Kabong" rides no more! But either seems a good name ("Baba Bluey" or "GoKart Mozart") for your replacement! Can't seem to come up with a suitable name for mine... Nothing has struck me yet...

(Oh, and sorry 'bout the minor thread detour, folks!)

 

Now back to our regularly scheduled programming.

 

After reading all these posts, I am THRILLED, that my 2010 Clubbie is getting, on average, 36mpg. Lucky me, my commute consists of twisty, hilly backroads, then a tad of city roads....wooohooooo

BTW: she has around 5400 miles on her so far.